The advancement and development of plastics has allowed for the design and production of a polymeric composite pickup truck cargo box. These pickup truck cargo boxes typically are comprised of a one-piece tub and a reinforced floor to which the one-piece tub is attached. The reinforced floor is typically fastened directly to a metallic frame of a vehicle. A conventional sheet metal fastener, by itself, cannot be utilized to attach the reinforced floor of the pickup truck cargo box to the vehicle's metallic frame, since the polymeric composite material cannot support a threaded fastener under the forces applied by the pickup truck cargo box. Due to the stiffness of the polymeric composite material, the load and the forces must be distributed over a broad area so as not to tear or puncture the reinforced floor of the pickup truck cargo box. Also, the polymeric composite pickup truck cargo box cannot be in direct contact with the metallic vehicle frame since prolonged contact will lead to the degradation of the polymeric composite material.